Age of Empires III: The WarChiefs is the first official expansion pack for the real-time strategy game Age of Empires III. It was announced by Ensemble Studios and Microsoft Game Studios on March 7, 2006. The demo version was released October 4, 2006. The full game for PC was released on October 17, 2006 in the United States. The expansion pack was then bundled with the full game of Age of Empires III, being called Age of Empires III Gold Edition on September 19, 2006. The Mac version was ported over, developed and published by Destineer's MacSoft Games. The full game for Mac was released on June 12, 2007 in the United States. It was followed by a second expansion pack to the original game called Age of Empires III: The Asian Dynasties.